In Saybolt's Electric Tester (1879) ignition is effected by a spark from an induction-coil passing between platinum points placed at a fixed distance above the oil.
The halogens may be estimated by ignition with quicklime, or by heating with nitric acid and silver nitrate in a sealed tube.
C. Gooch, which has come into common use in quantitative analysis where the solid matter has to be submitted to heating or ignition, consists of a crucible having a perforated bottom.
To tin cast-iron articles they must be decarburetted superficially by ignition within a bath of ferric oxide (powdered haematite or similar material), then cleaned with acid, and tinned by immersion, as explained above.
It is obtained from potassium tantalofluoride by heating with sulphuric acid to 400°, boiling out with water, and decomposing the residual compound of the oxide and sulphuric acid by ignition, preferably with the addition of ammonium carbonate.
Release of stored-up masses in the coal, which, overpowering the ventilation, produce magazines of explosive material ready for ignition when brought in contact with the flame of a lamp or the blast of a shot.
But there is a slight delay in ignition, partly due to expulsion of incombustible gas drawn into the jet tube in the previous half period, so that the most copious supply of gas and heat is thrown into the quarter period just preceding greatest pressure, and the vibration is maintained.
It can be made at a temperature as low as 300° C., and is then a soft, very friable material possessing a low ignition point.
When made at higher temperatures it is much more dense, and its ignition point is considerably higher.
Potassium iodide, KI, is obtained by dissolving iodine in potash, the deoxidation of the iodate being facilitated by the addition of charcoal before ignition, proceeding as with the bromide.
Chsm., 1850, 50, p. 358), by ignition of the carbonate, obtained the value 24.00 for the atomic weight, whilst C. Marignac, by converting the oxide into the sulphate, obtained the value 24.37.
Soc., 1901, 17, p. 63) by ignition of lanthanum sulphate at 500° C., the value obtained being 139 (O =16).
Beryllium is estimated quantitatively by precipitation with ammonia, and ignition to oxide.
It has been ingeniously suggested in this more scientific generation that the explosion was due to the ignition of some; forgotten store of oil or naphtha, such as was said to have been stored in the temple (2 Macc. i.
If an absolutely pure preparation is wanted it is best to follow Water and start with the "black flux" produced by the ignition of pure bitartrate.
This made the initial temperature so high at the moment of ignition that there was an explosion.
Dr. Goldschmidt obtained ignition of a cold mixture by means of a barium-peroxide fuse, which was set off by a storm match.
The salts of this acid, known as cyanides, may be prepared by the action of cyanogen or of gaseous hydrocyanic acid on a metal; by heating the carbonates or hydrooxides of the alkali metals in a current of hydrocyanic acid; by heating alkaline carbonates with carbon in the presence of free nitrogen: BaCO 3 + 4 C + N2 = Ba(NC) 2 + 3C0; by ignition of nitrogenous organic substances in the presence of alkaline carbonates or hydroxides; or by processes of double decomposition.
Chromic sulphide, Cr2S3, results on heating chromium and sulphur or on strongly heating the trioxide in a current of sulphuretted hydrogen; it forms a dark green crystalline powder, and on ignition gives the sesquioxide.
The same reaction is made use of in the quantitative determination of magnesium, the white precipitate of magnesium ammonium phosphate being converted by ignition into magnesium pyrophosphate and weighed as such.
Manganese may be estimated quantitatively by precipitation as carbonate, this salt being then converted into the oxide, Mn 3 0 4 by ignition; or by precipitation as hydrated dioxide by means of ammonia and bromine water, followed by ignition to NIn 3 0 4.
It forms a white friable mass which after ignition is insoluble in acids.
The sesquioxide, Cr 2 0 3, occurs native, and can be artificially obtained in several different ways, e.g., by igniting the corresponding hydroxide, or chromium trioxide, or ammonium bichromate, or by passing the vapours of chromium oxychloride through a red-hot tube, or by ignition of mercurous chromate.
Cadmium oxide, CdO, is a brown powder of specific gravity 6.5, which can be prepared by heating the metal in air or in oxygen; or by ignition of the nitrate or carbonate; by heating the metal to a white heat in a current of oxygen it is obtained as a dark red crystalline sublimate.
After ignition, it is allowed to cool in a desiccator and then weighed.
They are separated from the minerals by converting them into oxalates, which by ignition give the corresponding oxides.
On ignition, it loses oxygen and forms litharge.
When slowly heated in a vacuum vessel until ignition takes place, some nitrogen dioxide, N02, is also produced.
The precipitate, even after exhaustive washing with hot water, still contains a trace of alkali; but from the oxide, prepared from it by ignition, the alkali can be washed away.
On ignition the reaction, 8A1+3Fe 3 O 4 =9Fe+4Al 2 O 3, gives a temperature estimated to be between 2,300° and 2,700°C. The reaction, stated in weights, means that 217 parts of aluminium plus 732 parts magnetite (iron oxide) equals 540 parts steel plus 409 parts slag, or approximately 3 parts of aluminium plus 10 parts of magnetite will produce, on combustion, 7 parts of steel.
Dr. Goldschmidt's principal discovery related to a simple and safe method of ignition, as the action of aluminium when mixed with various oxides, sulphides, and chlorides was well known.
Indium oxide, In203, is a yellow powder which is formed on ignition of the hydroxide.
Its specific gravity is 0.59, and it melts at r80° C. It burns on ignition in air, and when strongly heated in an atmosphere of nitrogen it forms lithium nitride, Li 3 N.
Lithium oxide, Li 2 O, is obtained by burning the metal in oxygen, or by ignition of the nitrate.
A year later he noticed that spongy platinum in presence of oxygen can bring about the ignition of hydrogen, and utilized this fact to construct his "hydrogen lamp," the prototype of numerous devices for the self-ignition of coal-gas burners.
The monoxide is formed when the metal burns in air, but is usually prepared by the ignition of the nitrate, oxygen and oxides of nitrogen being liberated.
It can also be obtained by the ignition of an intimate mixture of the carbonate and carbon, and in small quantities by the ignition of the iodate.
Barium chloride, BaCl 2.2H 2 O, can be obtained by dissolving witherite in dilute hydrochloric acid, and also from heavy spar by ignition in a reverberatory furnace with a mixture of coal, limestone and calcium chloride, the barium chloride being extracted from the fused mass by water, leaving a residue of insoluble calcium sulphide.
The phosphorescence of the sulphide obtained by heating the thiosulphate is much increased by adding uranium, bismuth, or thorium before ignition pr.
Cupric oxide, CuO, occurs in nature as the mineral melaconite (q.v.), and can be obtained as a hygroscopic black powder by the gentle ignition of copper nitrate, carbonate or hydroxide; also by heating the hydroxide.
Ammonia does not react with tungsten or the dioxide, but with trioxide at a red heat a substance of the formula W 5 H 6 N 3 0 5 is obtained, which is insoluble in acids and alkalis and on ignition decomposes, evolving nitrogen, hydrogen and ammonia.
This sulphide is then by further heating converted into the oxide and finally reduced to the state of metal by ignition with carbon in clay crucibles.